How to repair a broken flex cable (Sony Xperia Z1 ...How to repair a broken flex cable (Sony Xperia Z1 microphone flex) In this guide I discuss the functionality of Sony Xperia Z1's

How to repair a broken flex cable (Sony XperiaZ1 microphone flex)

In this guide I discuss the functionality of Sony Xperia Z1's microphone, for it seems that themicrophone problems are fairly common. I will show where the microphone flex is usually torn

during repairs and an advanced technique for repairing the flex.

Scritto Da: Antti Immonen

How to repair a broken flex cable (Sony Xperia Z1 microphone flex) Bozza: 2017-10-27ID Guida: 63842 -

Questo documento Ã¨ stato generato su 2019-10-28 07:48:07 AM (MST).

© iFixit — CC BY-NC-SA it.iFixit.com Pagina 1 di 17




INTRODUZIONE

It indeed seems to be a fairly common problem for Sony Xperia Z1's microphone to stop working.There are different levels of microphone problems, and in this guide I will try to explain each of themas well as I can. You must have previous experience with surface-mount soldering, and obviouslydisassembling and reassembling the device is a piece of pre-requisite knowledge. This guide's mainobjectives are to show step by step how to make a jumper, advanced techniques on repairing flexcables (Yes, i know it is in most cases absurd to even consider bothering to fix a flex cable) and alsoto collect together scattered info about the Z1 microphone problems. Keep in mind, however, that allthis knowledge has no official source, only scattered forum posts around the web and my personalexperiences.

STRUMENTI:Microscope (1)Soldering Iron (1)Solder (1)Flux (1)Tweezers (1)Precision Utility Knife (1)




https://it.ifixit.com/Guida/Sony+Xperia+Z1+Touch+screen+Glass+Removal+Replacement/60971

Passo 1 — Diagnostics

To begin understanding theproblem, you should go to settings -> about phone -> diagnostics ->tests and test the functionality of themicrophone. Alternatively, you candial *#*#7378423#*#* and test themic in the service menu.

The test result is important forundestanding the problem. You canget muffled sound, no sound at all,or just buzzing. The test resultdefines what kind of actions youshould take to repair your device.

Also test the secondary microphone(used for things like recording soundfor video), it might come in handylater to know if it works.




Passo 2 — Exclude the obvious problems

Sometimes solving the problem canbe way simpler than anticipated, andtherefore you must exclude theobvious problems, such as pocketlint in the holes at the bottom of thephone, where the microphone picksup the air pressure changes that thephone interprets as sound.

So, check the holes at the bottom,and you might save yourself a lot ofwork. I have had this help for one ofmy customer's phone before. If thishelped you, great! If not - which itusually doesn't - don't worry.

Depending on the device inquestion, there can be washers,grounding pieces, or even plasticcovers above or between parts thatshould be checked and then re-checked if you have previouslyreplaced something inside thedevice. If not, it is possible thatreplacing the part, for example themicrophone, might help.

Keep in mind, that without theproper know-how, precision, andpatience, you can do more harmthan good to your electronic device ifyou try replacing things on yourown. Always exclude the simpleproblems and software problemsfirst before jumping to conclusionsand replacing a part.




Passo 3 — Software problems

You can try a hard reset, or updatingthe device's operating system orgoing back to an older, workingsystem. I will not go into detail aboutthe software side of the repair here,for I am way too ignorant of suchmatters to guide anyone about them.To find help look your device up onsites like xda developers.

I have come to believe that usuallyproblems that you have caused bymeddling with the devices softwareare only solved by fixing thesoftware.




https://it.ifixit.com/Guida/Sony+Xperia+Z1++Soft+-+Hard+Reset/29115

Passo 4 — Different symptoms

If you get muffled sound, you mostlikely do not have any problemswith the flex cables. This mightmean there is dirt somewhere, oryou have faulty mic settings.

No sound at all points to a brokenmic or damaged flex cables. If you(or anybody else) have neveropened up the device you do nothave a broken flex. They don't breakon their own.

Buzzing noise might meandamaged mic (water, moisture...) orsome faulty mic settings. For somepeople, disabling mic noisesuppression and equalizer havehelped.




Passo 5 — Broken hardware

If you have had no problems withthe mic prior to an operation on thephone that requires opening up thedevice, but problems appear rightafter, chances are, a mistake wasmade at some point.

For Xperia Z series it seems to be acommon problem that upon screenreplacement the microphone goesmute. And the culprit is almostalways the flex cable. Evenexperienced people make mistakessometimes, and flex damage is avery common thing to go wrongduring the screen replacement. Andthat is what this guide is about.

Other possibilities includeA surface-mount component hasbeen knocked off the board or onthe flex.

There is dirt or a bad connectionbetween the flex and themotherboard, or between the partand the flex.




Passo 6 — Spotting the broken flex

To find a broken flex you will need to obviously focus on the flex cables and areas of flex cablesthat were touched during the previous repair. For Xperia Z1, the problematic cable is the large flexcable that leads from the motherboard to all the buttons and the screen.

You will need a keen (or experienced) eye to spot a damaged flex cable by eye, and thereforesome magnification is recommended.

Note how the tear was under the black rubber that has been peeled upward to uncover the torntrace. Sometimes it can indeed be difficult to spot the defective points.

The flex commonly tears near a bend in the flex or in a narrower area. See the pictures from twobroken mic flexes for Z1. The first image is the original flex which I accidentally tore and the secondis a replacement which arrived broken. Not trusting the second replacement to be ok, I repaired theoriginal...




Passo 7 — Buying the new flex

Finding the broken flex is usually theend of the diagnostics part, and thereplacement pieces are oftentimesfairly cheap.

When ordering a new part, doublecheck the model numbers and thepictures to ensure compatibility.

For iPhone 6 home button flex cablerepairers (Error 53) , or people whodo not have the time to wait for anew part, I will include thesefollowing parts more as a curiositythan actually something worth doingas common practice. Unless youdon't have a good reason (or enjoy itlike I do) don't fix a broken flexcable. It rarely is worth it.




Passo 8 — Planning the repair

If you have decided to fix a flexcable, you must have a good planwhere to attach jumpers from andwhere they will lead to. Good jumperpoints are for example the sides ofSMD components, or broader areasof the trace. I have circled a fewpotential points for jumpers fordifferent traces in the picture, so thatyou get the general idea.

You must understand the concept ofjumpers to successfully make ajumper on the flex. The wire has tobe insulated, or you will end up withstrange connections and damage.Enameled copper wire is somethingI personally use a lot, or sometimespieces of scrap flex cable (moredifficult).

Look for as much free space aspossible for the jumper points toavoid knocking over SMDcomponents with your solderingiron. It is also possible toaccidentally burn or desolder acomponent, so I would advice tofavor the free, empty pads forjumpers.

Keep in mind the routing of the flexcable inside the device to avoidplacing solder and jumpers wherethere isnt room for them.




Avoid using hot air, this can burnand warp the flex. You must domost of this by hand soldering usingan iron, so previous SMTexperience and a microscope are aMUST.

See the next steps of the guidebefore cutting your jumper to get thegeneral idea of what kind of ajumper you're looking to make.

Passo 9 — Cleaning pads

After locating an auspicious looking pad, scratch it with the tip of an exacto knife until the copper isexposed.

Be extra careful with the knife; don't press hard. You might have to gently scratch the surface forhalf a minute for the copper to show. Practice this (and actually all parts of this repair procedure)on scrap flex cables.

Proceed to clean the pad with alcohol (not under the influence, though), and a Q-tip.

Do the same procedure for the second jumper point.




Passo 10 — Tinning the pads and the jumper

Spread flux onto the pads, and with your soldering iron gently touch the pads with the tip of theiron with some solder to tin them. See the pictures and practice this beforehand. In the secondpicture the pad has received a smaller tinning due to insufficient cleaning done to the pad. Go forlarger solder pads than that if you have the space.

Also tin the ends of your jumper. To remove enamel on the jumper, use a file or a knife, and thenwith lots of flux add some solder (Not a lot!) onto the end of the jumper. It is enough to see that theend of the jumper is silvery. A large blob of solder is bad.




Passo 11 — Soldering the jumper

Add more flux (Jessa quote)

Avoid leaving any exposed wire after the solder contact - this can and will touch other componentsand **** up the device. Check the first picture: I am leaving all the extra tinned section of the wire tobe cut off later. Even now there is an empty pad slightly too close for my liking (circled in red).

Carefully solder the jumper into place, holding it with tweezers. Don't worry about the length of thejumper yet.

In the second picture, a solder bridge has formed, due to too much solder used. I believe this is agood example of failed soldering, of what can happen if you're not careful. But, in this case, thebridging didn't matter (check the first pic to see why) so I just let it be.

The pad that was already a little bit too close now got way too close, and I ended up wiggling apiece of tape as insulation in between the jumper wire and the pad after cleaning the area of flux.




https://www.ifixit.com/User/About/739239/jessabethany

Passo 12 — Soldering the jumper cont'd

Measure the jumper to easily reach the pad you're going for. Remember to route the jumper flatacross the flex. If the flex needs to bend somewhere on the way, make sure the jumper wire is longenough. Also keep in mind that you should never use copper wire to repair flexes that need tomove in the device, for it will without doubt, break.

Poke the wire a couple times with a file to expose copper if your earlier tinning is insufficient, andonly enough to solder onto. And then tin the wire again.

Add more flux.

Solder. Apologies for bad pic quality. In the second picture, I have also already cut the extra wireoff.




Passo 13 — Removing the excess wire

Grab the excess wire with your tweezers, and bending back and forth, gently snap it off. Repeatthe same procedure for the other end.

If you break your solder joint by twitching the leftover wire carefully back and forth, the joint wastoo weak to begin with.




Repeat the same procedure for all torn flex traces and you're done. Good luck. And also, if you doattempt this, post your results here, and if possible, send me pictures of your results. And mostimportantly, if you're an expert reading this, please take the time to correct me if I do something wrong.

Passo 14 — Cleaning

Wipe away all the flux with a Q-tipand some IPA (Isopropyl Alcohol).Never spray "IPA" straight onto themic, or anywhere near the screen, itmight cause distortion later on in themic and color distortions betweenthe LCD layers.

Tape and or glue the torn parts ofthe flex cable so that it doesn't tearfurther. Never use super glue forgluing, rather use epoxy or such. Ipersonally added a drop of epoxyand then taped around it to create aneat package around the torn flex.

I also had to cut a small hole in themic enclosure for my jumper wire tofit through atop the flex nicely.




Documents

How to repair a broken flex cable (Sony Xperia Z1 ...How to repair a broken flex cable (Sony Xperia Z1 microphone flex) In this guide I discuss the functionality of Sony Xperia Z1's